The natural lens of an eye is lenticular-shaped body having three portions. The core portion is the nucleus which is surrounded by a cortex. Enclosing the cortex and constituting the wall of the lens is the capsule. The degenerating or degenerated lens of an eye, or a localized point of degeneration within a lens is referred to as a cataract. As a result of a cataractous degeneration, the lens becomes opaque, resulting in visual disability.
Numerous surgical procedures have been developed for removal of cataracted lenses including intracapsular extraction and extracapsular extraction. When the cataract is removed without breaking the capsule, such that the lens is entirely removed, an intracapsular extraction is performed. By contrast, when the forward facing, anterior portion of the capsule is removed followed by separate removal of the lens contents, an extracapsular extraction is performed. Generally, in an extracapsular extraction, the posterior portion of the lens capsule remains in the eye.
In extracapsular cataract extraction, an incision is made into the eye, and the anterior capsule is removed The size of the nucleus dictates the size of the incision which must be made for the cataracted lens to be extracted. An incision of six millimeters to ten millimeters is commonly employed with this technique. During the process of removal of the lens, the lens is moved into the anterior chamber of the eye. The lens may contact the corneal endothelium of the eye resulting in damage of this tissue.
A need has thus arisen for an ophthalmic surgical instrument and method for removing a lens of the eye to thereby minimize any damage to the endothelium layer of the eye In such a procedure, containment of the lens must be accomplished within the posterior chamber prior to removal through the incision made in the eye.